Differential diagnosis
Differential diagnosis includes infectious spondylodiscitis (pyogenic, brucellar, tuberculous, mycotic, protozoan), neoplasms of the spine (primary or metastatic), spondyloarthropathies (ankylosing spondylitis, reactive arthritis, psoriatic arthritis), Paget disease, and hematologic neoplasms (chronic leukemias, multiple myeloma).

Diagnosis
Tuberculous spondylodiscitis (Pott's disease). Culture of the extracted bone grew Mycobacterium tuberculosis, which was resistant to isoniazid and rifampin.

Therapy
The patient was treated with pyrazinamide 1500 mg, ethambutol 1200 mg, streptomycin 1 gr, ofloxacin 800 mg, cycloserine 750 mg and vitamin B6 62,5 mg per day. Her symptoms gradually receded. Streptomycin was discontinued after two months of treatment. The rest of antituberculous agents were discontinued five months after initiation of treatment due to severe drug-related hepatotoxicity and psychosis. After treatment discontinuation all adverse reactions subsided. Four and a half years later the patient continues to be free of symptoms and with normal ESR without taking any medications.

Teaching points

• The involvement of the intervertebral disc favours the diagnosis of an infectious process and not a neoplastic disease.
• Our patient presented with the challenges of the management of spondylodiscitis. Persistent and even invasive diagnostic work up is needed for the proper and prompt management of these patients. Even then percutaneous approaches to obtain material from the infectious area have a sensitivity of 72% though specificity reaches 94% [1].
• Multidrug resistant tuberculosis is an important emerging threat to human health globally [2-4]. In vitro drug susceptibility testing may be necessary for all Mycobacterium tuberculosis isolates due to the increasing incidence of multidrug resistant strains worldwide. This is particularly so, as inadequate treatment may lead to increasing resistance [5].
• Psychosis has been an established possible complication of cycloserine and isoniazid treatment. Less often ethambutol, quinolones, and rifampin have been reported to cause psychosis.

Reference List

1. Fouquet B, Goupille P, Gobert F, Cotty P, Roulot B, Valat JP. Infectious discitis diagnostic contribution of laboratory tests and percutaneous discovertebral biopsy. Rev Rhum Engl Ed 1996; 63(1):24-29.
2. Abe C, Hirano K, Wada M, Aoyagi T. Resistance of Mycobacterium tuberculosis to four first-line anti-tuberculosis drugs in Japan, 1997. Int J Tuberc Lung Dis 2001; 5(1):46-52.
3. Miah MR, Ali MS, Saleh AA, Sattar H. Primary drug resistance pattern of mycobacterium tuberculosis in Dhaka, Bangladesh. Bangladesh Med Res Counc Bull 2000; 26(2):33-40.
4. Stauffer F, Makristathis A, Klein JP, Barousch W. Drug resistance rates of Mycobacterium tuberculosis strains in Austria between 1995 and 1998 and molecular typing of multidrug-resistant isolates. The Austrian Drug Resistant Tuberculosis Study Group. Epidemiol Infect 2000; 124(3):523-528.
5. Furin JJ, Becerra MC, Shin SS, Kim JY, Bayona J, Farmer PE. Effect of administering short-course, standardized regimens in individuals infected with drug-resistant Mycobacterium tuberculosis strains. Eur J Clin Microbiol Infect Dis 2000; 19(2):132-136.

Acknowledgments

1. This case was prepared for our website by P. Rafailidis, MD and P. I. Vergidis, MD.
2. We thank I. Avramopoulos MD, G. Sapkas, MD, and I. Xinotroulas, MD, for their contribution in the management of the case.